docs: def get_main_section(self, linesep=None):
          """
          Serialize just the main section of the manifest and return it as bytes
          :return bytes
          """
  
          linesep = linesep or self.linesep or os.linesep
  
          stream = BytesIO()
          ManifestSection.store(self, stream, linesep)
          return stream.getvalue()